SPL (Sound Pressure Level): A measurement of the volume of sound, expressed in decibels (dB): a function of amplitude.
Sensitivity: The sound pressure level directly in front of the speaker (on axis) at a given distance and produced by a given amount of power.
Shield: A metal enclosure that prevents electronic components from being affected by unwanted interference. Shielded speakers may be placed near a TV, for instance, because their magnets cannot affect the picture tube.
Shelving: The setting of the on-axis output of complementary drivers (woofers, mid-range, tweeters) to provide the desired frequency response.
Sibilance: A hissing sound produced when pronouncing S and Z. Sibilance is undesirable in professional sound reinforcement and can be controlled through the use of a de-esser like Valley Audio’s 401 Microphone Processor, 815 Dynamic Sibilance Processor, or 730 DynaMap Digital Dynamics Processor.
Signal: An electrical impulse.
Signal-to-Noise-Ratio: The ratio, expressed in dB, of an electronic device’s nominal output to its noise floor.
Snake: A cable – often running between the stage and control board – that combines multiple lines; used to connect mics, instruments and monitors to a mixer.
Sound Level Meter: A device that measures, in dB, the amplitude of sound waves.
Sound Pressure Level (SPL): The measurement of the loudness, or amplitude, of sound, expressed in dB.
Sound Reinforcement: The use of electronic devices to reinforce, alter or increase the level of sound.
Spider: An internal speaker component whose function is to precisely position the voice coil in relation to a gap in the motor.
Splowt : A unit of measure, expressed as dB, that divides a speaker’s maximum SPL by its weight in pounds. Galaxy Audio’s MICRO SPOT boasts a splowt of 43 dB (highest in the known universe).
Supercool: To cool (a liquid) below a transition temperature without the transition occurring, especially to cool below the freezing point without solidification.